Hospital beds have traditionally had some type of collapsible side rail on each side of the mattress, so that a patient on the bed cannot inadvertently roll off of the bed and receive serious injuries from a fall to the floor. One conventional type of collapsible side rail includes a plurality of arms which are each supported at one end on a frame of the bed for pivotal movement about a horizontal first pivot axis extending transversely of the bed, and which each have an opposite end supported on a horizontally extending top rail for pivotal movement about a horizontal second axis parallel to the first. The arms are pivotal between an operational position in which the arms are upright and the top rail is disposed above the mattress surface, and a retracted position in which the arms extend approximately horizontally and the top rail is disposed below the top of the mattress. When this conventional side rail is in the collapsed or retracted position, it is still disposed laterally outwardly of the mattress. Consequently, when two beds are placed immediately adjacent each other to facilitate the transfer of a patient from one bed to another, the side rails of each bed serve to keep the mattresses spaced somewhat from each other, and thus hospital personnel must manually lift a patient across the relatively large gap between the mattresses.
As a result of this problem, there have been efforts in recent years to develop a side rail which, in the retracted position, is below and laterally inwardly of an edge portion of the bed, so that when two beds are placed together for purposes of patient transfer the side rails are not between and do not cause a forced spacing of the edge portions, but instead the edge portions can be placed directly against each other. One known approach is to provide additional arms which extend horizontally between and are pivotally coupled by vertical pivot axes to a stationary bed frame and a support member, the arms of the side rail itself being pivotally supported on the laterally movable support member. This known arrangement is, however, complex in structure and therefore expensive to manufacture and cumbersome to use.
An alternative known approach is to provide two transversely extending slide rods on the bed frame and to slidably support a subframe on these members for lateral movement relative to the bed, the arms of the side rail being pivotally supported on the laterally movable subframe. Again, however, the resulting arrangement is structurally complex, and therefore expensive to manufacture and cumbersome to use. Further, if either end of the subframe is moved laterally a little faster than the other end, the subframe can frictionally bind with respect to the transversely extending slide rods, and dependable lateral movement is thus difficult to achieve.
An object of the present invention is therefore to provide an improved arrangement for supporting a side rail for movement between operational and retracted positions in a manner so that the side rail moves downwardly and inwardly as it moves into its retracted positions, which mechanism is structurally simple and is therefore inexpensive to manufacture and easy to operate.
A further object is to provide such an arrangement which can also be satisfactorily used to support other components on a bed, such as an IV pole, a foot support stirrup, leg support, hand grip, or push handle.